It doesn't work like this.
Let's say you have a Thai bank account and at the end of each month 58,745 Baht arrive from Happy Lucky Brighter Fortune Co. Purpose of the transfer is stated every time as "salary". Looks a lot like a salary, right?
Now let's say you have a Thai bank account and at the end of January you get 75,876 Baht from Happy Lucky Brighter Fortune Co. At the end of February you get 34,364 Baht from them. Purpose is stated as "January 2023", "February 2023" and so on. This goes on every month, except for December, where the money - 123,456 Baht - arrives earlier, at Dec 20th, and is stated as "December 2023 incl. Christmas bonus". Looks like what?
Now, if you have a Thai bank account and you get 556,000 Baht on May 15th from Mrs Sabaiguy, stated as "for purchase of used Honda Civic", and on Aug. 7th you receive 300,000 Baht from your own foreign account stated as "living expenses", nobody is going to ask stupid questions.